Thermostatic control of cooling circulation



Nov. 12, 1929. w. B. CLIFFORD THERMOSTATIC CONTROL OF COOLINGCIRCULATION Filed Nov. 24, 1926 [MW 0 WW a 6% T l 5 2 Patented Nov. 12,1929 UNITED STATES PATENT OFFICE WALTER B. CLIFFORD, F CAMBRIDGE,MASSACHUSETTS, ASSIGNOR TO CLIFFORD MANUFACTURING 00., 0FBGSTON,'MASSACHUSETTS, A CORPORATION OF DELA- WARE THERMOSTATIC CONTROLOF COOLING CIRCULATION Application filed November 24, 1926. Serial No.150,581

The present invention relates to improvements in apparatus forcontrolling cooling fluid flow of an internal combustion motorthermostatically, and more particularly to to an apparatus of thischaracter employed in motor vehicles.

In a typical installation of this character athermostatically-controlled valve is inserted directly in thecirculating system,

either adjacent to the upper portion of the motor block or the upperportion of the radiator. This valve remains closed, retarding orcompletely stopping circulation through the block until the temperatureof the cooling fluid therein has been elevated'to a predetermined point.Thereafter, operation of the thermostat opens the valve and permitscirculation of water, or othercooling fluid, into and through theradiator.

In typical installations of this character the valve is designed to openfrom 135 to 165"' F, depending upon the circulating system and thelocation of the valve. Ordinarily. when the thermostat unit is locatedin the radiator inlet, the valve is caused to open at a lowertemperature than when the unit is located in immediate proximity to themotor block. In either event, it is desir able that when thepredetermined temperat-ure within the circulating system has beenreached that the valve shall open as rapidly as possible and permit arelatively free circulation of water with a minimum rise of temperatureabove the opening point.

To this end the primary object of the present invention is to provide athermostatically controlled unit in which the range or spread oftemperature from commencement of opening-to full opening of the valve isreduced to a minimum.

. With this and other objects in view, therefore, the various featuresof the invention consist in certain novel features of construction,combinations and arrangements of parts the preferred form 0 theinvention,

Fig. 1 represents a section in elevation of an installation embodyingthe features of the invention; and

Fig. 2 is a cross section taken upon the line 2--2 of Fig. 1:

Referring to the drawings, the top of the cylinder block is indicated at10, and has connected theretoa sleeve casting 12 which encloses athermostatic unit 14. The casting is provided interiorly with a chamber16 communicating directly with the water space 18 of the block andpermitting the passage of water upwardly about the thermostatic unit.The upper portion of the sleeve casting is surmounted by an outletcasting 20, which is adapted tobe connected in any desired mannor withthe usual radiator connections. T he entire assembly is rigidlyconnected to the top of the cylinder block by through bolts 22. Thethermostatic unit comprises essentially a thin drawn or stamped shell 30having a series of openings 3% for the free passage of water. Mountedwithin the shell is a metallic bellows 34 rigidly connected to the shellat the closed end by a threaded stud 36 and nut 40. The opposite freeend of the bellows carries an elongated stud 42 upon the upper end onwhich is mounted a valve 44. This valve is retained in adjusted positionuponthe stud by a nut 46 and a spring '48 surrounding the stud andholding the valve against the nut.'

Mounted on the stud below the valve is a stop member 50 held against ashoulder 52 by the spring 48, and comprising generally radiating arms 54which engage with the under side of an annulus 56 to limit the openingmovement of the valve. The annulus 56, as indicated particularly in Fig.1, is formed by a bent metal strip clamped in the upper portion of theshell 30 by the inturned flange 60. This annulus not only limits theupward movement of the valve but the upper portion of the annulusconstitutes a seat for the valve 44 when in the closed position shown inthe drawing. As will be evident to those skilled in the art, themetallic bellows is filled with a vaporizable. liquid at a pressuresubstantially less than atmospheric, and for all temperatures below thepredetermined opening point exerts a pull upon the valve sufficient tomaintain it in closed position against the head of inner portion of thevalve from whence the water therebeneath. When the predeterdirection offlow is reversed in contact with mined opening point is reached, thewater the annular chamber to exert'a reaction efl'ect head, due to theaction of the pump, is suifion the valve. cient to overcome the pull ofthe bellows WALTER B. CLIFFORD.

which has been reduced by increase of vapor pressure therein, and thevalve opens. According to the present invention, this opening tendencyis reatly accentuated by a velocity or reaction ead created through thenovel 7 shape of the valve. As will be observed from an inspection ofFig. 1, the valve 44 is provided with a raised annular portion 65inter-- mediate its inner and outer circumferences to 1f0rm a reverselycurved annular chamber at the under side of the head, of such acharacter that the water is turned through 180 degrees and a substantialreaction eifect is exerted thereby. It will be evident that when thevalve rises from its seat, the water current,

due to its substantial change in direction, exerts a reaction effecttending to further elevate the valve without an increase in pressurehead. This substantial addition to the elevating force beneath the valvecauses it to open with a range of temperature materially less than wouldbe possible if the pressure head alone were relied upon. After the waterhas passed from beneath the valve, it is guided upwardly by theconverging walls 67 shaped to avoid the formation of an edd current andto reduce the desired reaction e ect. In connection with the'utilizationof this velocity. head, it will be noted that the arms 54 of the '35stop member 50 are relatively thin transversely of the direction of flowof the water, and are relatively thicker in the direction of flow, whichis accomplished by stamping the arms from a thin sheet and thereafterturning the 40 arms through an angle of 90 with the plane of the sheet.This causes the arms, in fully .open position, to present the leastobstruction to the water way and avoids so far as possible, theformation of undesirable eddy currents 4.5 below the valve.

Whatis claimed is 1. Temperature-controlled apparatus comprisingmetallic bellows, an open cage connected withthe bellows at one end, avalve opening formed in the cage, a valve connected with the oppositeend of the bellows and cooperating with the opening, the valve beingshaped and designed in conjunction With the valve opening to reverse thedirection of flow of water therebeneath upon opening in a manner tocause the exertion of a substantial re action head in a direction toopen the valve.

Temperature-controlled apparatus comprising an expansible metallicbellows, a cage connected to the bellows at oneend having a valveopening therein, a valve connected with the free end of the bellows andhaving a re-' versely-curved, annular chamber adjacent the valveopening, and means for directing liquid fi fiow.through the valveopening against the

